JP3684271B2 - Power module - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement of a power module in which a heat sink is fixed to a semiconductor element.
[0002]
[Prior art]
This type of prior art is disclosed in, for example, Japanese Patent Publication No. 7-28153. In this prior art, a printed circuit board and a power amplifying semiconductor are fixed to a heat sink using solder or the like. In a high-frequency multistage power amplifier circuit in which the printed circuit board is covered with a metal cap, the surface of the heat sink is solder plated. Was.
[0003]
[Problems to be solved by the invention]
However, in the case of the above-described prior art, the heat radiating plate and the metal cap are configured as separate parts. Therefore, not only the cost of parts becomes high, but also man-hours for combining both parts are required.
[0004]
This invention solves the above-mentioned subject, and it aims at providing the power module which can perform the heat radiation and electromagnetic shielding of a semiconductor element with one heat sink, and is excellent in the mounting property to a substrate etc. It is what.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, first, the invention according to claim 1 is a power module including a heat dissipation plate that is fixed to a semiconductor element and that dissipates heat generated by the semiconductor element. forming a housing as to surround the periphery of the element, Ri substantially T-shaped der deployment shape before bending of the heat radiating plate, and the end portion of the heat radiating plate, a step between the fixed portion of the semiconductor element The power module is provided, wherein the terminal of the semiconductor element is bent and the tip thereof is aligned with the surface formed by the end of the heat sink .
[0010]
DETAILED DESCRIPTION OF THE INVENTION
1st Embodiment of this invention is described based on FIGS. 1-3. The power module shown in the first embodiment exemplifies a form suitable for mounting horizontally on a printed circuit board. Reference numeral 1 in the drawing denotes a semiconductor element in which a power MOS FET or the like that can control a load with a large current consumption, such as a vehicle direction indicator lamp, is connected to a printed circuit board (not shown). A terminal 11 is provided.
[0011]
Reference numeral 2 denotes a heat radiating plate that is fixed to the semiconductor element 1 and radiates heat generated by the semiconductor element 1. As shown in FIG. 3, the heat dissipation plate 2 has a substantially T-shaped unfolded shape, and surrounds the periphery of the semiconductor element 1 by bending portions of the fold lines a to f indicated by alternate long and short dash lines in FIG. 3. It forms a box like this. Then, the end portions 21 and 22 of the heat radiating plate 2 are bent and protruded laterally, and a step 24 is provided between the end portions 21 and 22 and the fixing portion 23 of the semiconductor element 1 as shown in FIG. Yes. The dimension t of the step 24 may be a dimension that allows other elements to be arranged in the space formed by the step 24, and is set to about t = 2 to 8 [mm], for example.
[0012]
Moreover, the heat sink 2 has holes 25 and 26 at the end portions 21 and 22, and screws (not shown) are inserted into the holes 25 and 26 to fix the heat sink 2 to the printed circuit board. If the heat radiating plate 2 is made of a solderable material, it can be fixed to the printed circuit board by soldering.
[0013]
Further, the end portion 11 of the semiconductor element 1 is bent stepwise as shown in FIGS. 1 and 2, and the tip 12 thereof is aligned on the surface formed by the end portions 21 and 22 of the heat radiating plate 2. . Thereby, when the heat sink 2 is fixed to the printed board, a small gap is generated between the tip 12 of the terminal 11 and the conductive pattern of the printed board. Therefore, for example, when each element mounted on a printed board is soldered by a reflow bath or the like, the solder penetrates into the gap due to a capillary phenomenon, and the reliability of soldering is improved.
[0014]
Next, a second embodiment of the present invention will be described with reference to FIG. The power module shown in the second embodiment exemplifies a form suitable for mounting vertically on a printed circuit board. The power module of the second embodiment has a structure in which the terminal 11 is not bent and can be inserted into the hole of the printed circuit board and soldered as it is. Other structures are basically the same as those shown in the first embodiment, and detailed description thereof is omitted.
[0015]
【The invention's effect】
According to the first aspect of the present invention, as described above, in the power module including the heat sink fixed to the semiconductor element and dissipating the heat generated by the semiconductor element, the heat sink is bent to surround the semiconductor element. Since the unfolded shape of the heat radiating plate before bending is substantially T-shaped, the semiconductor element can be radiated and electromagnetically shielded by one heat radiating plate. And the like is easy to bend.
Further, according to the invention of claim 1, wherein an end portion of the radiator plate, is provided with the step between the fixing portion of the semiconductor element, can be arranged other elements in a space stepped forms There is an effect that the power module of the present invention and other elements can be three-dimensionally mounted on a substrate or the like.
Further, according to the first aspect of the present invention, since the tip by bending the terminal of the semiconductor device are aligned on a plane end forms of the heat radiating plate, when fixing the radiator plate to the printed circuit board, terminals A small gap is generated between the tip of the printed circuit board and the conductive pattern of the printed circuit board, and when each element mounted on the printed circuit board is soldered by a reflow bath or the like, the solder penetrates into the gap due to a capillary phenomenon, and the reliability of soldering The effect is improved.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a first embodiment of the present invention.
FIG. 2 is a side view in the direction of arrow A shown in FIG.
FIG. 3 is a perspective view showing a state before the heat sink shown in FIG. 1 is bent.
FIG. 4 is a perspective view showing a second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Semiconductor element 2 Heat sink 11 Terminal 12 Tip 21, 22 End part 23 Adhering part 24 Step 25, 26 Hole

Claims (1)

In a power module provided with a heat radiating plate (2) that adheres to the semiconductor element (1) and radiates heat generated by the semiconductor element (1).
Said folded radiating plate (2) forming a housing as to surround the periphery of the semiconductor element (1), Ri substantially T-shaped der deployment shape before bending the heat radiating plate (2),
A step (24) is provided between the end portions (21, 22) of the heat sink (2) and the fixing portion (23) of the semiconductor element (1),
A power module characterized in that the terminal (11) of the semiconductor element (1) is bent and its tip (12) is aligned with the surface formed by the ends (21, 22) of the heat sink (2) .

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